If you’re an experienced reptile keeper and are interested in adding a large lizard to your collection, the rhino iguana, Cyclura cornuta, may be the lizard for you.
These lizards are hardy, full of personality, intelligent, and long-lived. However, keeping rhino iguanas isn’t without its challenges.
This guide will provide information on this species and its husbandry requirements.
In This Article
- Rhino iguanas are high maintenance, and their upfront costs are expensive.
- Rhino iguanas are an endangered species, so you can only obtain captive-born specimens.
- Because rhino iguanas live for up to 20 years, getting one is a long-term commitment.
- Rhino iguanas aren’t for beginner reptile keepers or those who lack experience keeping large lizards.
- Major costs for this animal include: large enclosures, clustered UVB lighting, deep substrates, dietary needs, and the iguana itself.
Though we have a lot of information about the care and breeding of rhino iguanas, we know little about how they live in the wild.
These lizards come from remote tropical islands in the Dominican Republic, and their population is dwindling, so this species hasn’t been widely studied.
Cyclura cornuta is a member of the Iguanid family, also known as the “true iguanas.” This large and diverse group of lizards includes the following genera:
- Iguana (Green Iguana)
- Cyclura (Rhino Iguana)
- Sauromalus (Chuckawalla)
- Brachylophus (Fiji Iguanas)
- Dipsosaurus (Desert Iguana)
- Ctenosaura (Spiny-tailed Iguana)
- Amblyrhynchus (Marine Iguanas)
- Conolophus (Galapagos Land Iguana)
The members of this family have pleurodont dentition, which means that their teeth are positioned inside the jaw bone.
Rather than having sockets, the teeth are fused to the jaw bone and they can replace them indefinitely. Some members of this family also live in the tropics.
This family of lizards has adapted to a wide variety of conditions. It contains species that arrange from being herbivorous to carnivorous and terrestrial to arboreal.
Rhino iguanas occur exclusively on Hispaniola, an island in the Dominican Republic. There were subspecies of rhino iguanas on the island of Navassa, but they’re now extinct.
There are living populations of a rhino iguana subspecies on Mona Island, located near Puerto Rico.
The natural habitat of the rhino iguana is found along the coastline, and varies from desert to scrub and dry forest.
It’s an area with minimal rainfall and an abundance of sunshine. The average temperature of this area is 80°F (27°C).
The typical plant life of this area includes mesquite, cacti, shrubs, and small trees.
The rhinoceros iguana is terrestrial, and digs burrows for shelter.
It’s important to keep in mind that this iguana species comes from a habitat with high temperatures and a lot of solar radiation since it affects their needs in captivity.
Rhino iguanas are diurnal and spend much of the day either eating or basking.
They’re the dominant herbivore in their habitat, though they sometimes eat meat. They sometimes eat insects.
Rhino iguanas support the ecosystem by helping plants to spread their seeds.
These iguanas aren’t able to digest the seeds of fruits. As a result, the seeds are left unharmed and expelled with the lizard’s feces.
As they’re herbivores, their diet is variable as it’s seasonal. Their diet includes a wide range of leaves, flowers, and fruits.
Rhino iguanas will eat meat and we know they eat carrion, land crabs, and insects. Juvenile rhino iguanas, in particular, will eat insects and small animals.
When rhino iguanas find a food source, they’ll defend it from other iguanas.
Fun Fact: Iguanas, like other herbivores, have an extra-large digestive tract. It contains bacteria that digests the cellulose from plant matter.
Unlike most lizards, several species of iguanas demonstrate complex social behaviors. The rhinoceros iguana is one of those species.
In the wild, rhino iguanas gather in groups when food is abundant. They have a social hierarchy that allows them to maintain order during such times.
It’s also handy during the breeding season when males become very territorial.
Rhino iguanas can recognize the social standing of other rhino iguanas and adjust their behavior accordingly.
Head bobbing is a commonly used form of communication. It’s used to express:
- Dominance: Rapid head bobbing by dominant males is a warning to other males.
- Submission: Slower head bobbing is used to express submission.
- Sexual Interest: Slower head bobbing is also used to express sexual interest.
Adult male rhino iguanas engage in bobbing their heads more frequently than females or younger males.
Male rhino iguanas will assume a variety of postures when threatened by predators or other male iguanas. These postures include:
- Tail whipping
- Bobbing their head
- Inflating their bodies
- Extending their dewlap
If the threat is another male rhino iguana, they’ll fight if the other male doesn’t submit. Male rhinos use their teeth and tails when battling with each other.
Given that the horn-like protrusions are larger in males, they probably also use those to communicate dominance.
Rhino iguanas range in color from grayish to olive. The color of the iguana’s body allows it to blend in with its surroundings.
Some of the scales on their head are large, particularly the horn-like protrusions from which it gets its name. The iguana’s body has a prehistoric appearance.
They have large triangular heads, and their large bodies have spines running down the back and along part of the tail. They’re also equipped with powerful claws.
Fun Fact: The rhinoceros iguana was discovered in 1789 by Pierre Joseph Bonnaterre. Bonnaterre named this reptile after the horn-like protrusion on the lizard’s snout.
Rhino iguanas can attain a length of 4½ feet, though they usually reach a smaller size. Their weight ranges from 10-20 lbs.
Rhino iguanas have a slow growth rate, and it can take three years or longer for them to reach full size.
The following is a breakdown of size by age:
Length (L) is measured from snout to tail (inches), and weight (W) is in pounds.
- Hatchling: (L) 6-9, (W) 90 gms.
- 1 year: (L) 20-27, (W) 1-1.5.
- 2 years: (L) 28-36, (W) 2-4.
- 3 years: (L) 30-42, (W) 4-6.
- 4 years: (L) 35-48, (W) 5-8.
- 5 years: (L) 50-66, (W) 14-18.
- 6 years: (L) 45-60, (W) 10-15.
- 7 years: (L) 50-72, (W) 15-20.
Rhino iguanas are challenging to keep because of their husbandry requirements and the budget needed to meet those requirements.
The following sections outline the requirements for this iguana species.
One of the greatest challenges of keeping a pet rhino iguana is the enclosure size they require.
The minimum size for an adult rhinoceros iguana enclosure is 8′ L x 4′ H x 4’ W. Rhino iguanas need plenty of room.
Because of its size requirement, you’ll probably have to have someone custom-build the rhino iguana enclosure.
You can keep young iguanas (up to six months) in an enclosure measuring 24″ x 18″ x 36″.
The lighting for your rhino iguana will be the most expensive part of the enclosure.
In the wild, rhino iguanas spend much of their time basking in the sun. You must equip the indoor enclosure with UVB lighting.
Rhino iguanas are large lizards. It spends a lot of time under the UVB lamp in an attempt to heat its entire body.
If you only have one UVB lamp, the bulb’s heat will concentrate on a part of the rhino iguana’s body. This often results in burns.
Because of the size of the enclosure and the lizard, you need multiple UVB bulbs.
We recommend having three to four UVB bulbs that are clustered together.
Setting up the lighting this way will also provide the UVB lighting needed to prevent metabolic bone disease.
If you’re fortunate enough to live in a tropical climate, you can keep your rhino iguana in an outdoor exhibit. In this case, you won’t need UVB lighting!
The ambient temperature for the rhino iguana enclosure should be approximately 80°F, while the basking temperature should be between 90-95°F.
Keep two reliable thermometers in the enclosure to monitor both the ambient and the basking temperature.
If you keep your rhino iguanas outside, make sure that they have a heated hide box for when the weather becomes cooler.
You should also ensure that your rhino iguanas have plenty of shade during the warmer months.
Though rhino iguanas are naturally found in areas that receive minimum rainfall, that doesn’t mean the humidity level isn’t important!
Keep in mind that they live on islands, so the humidity level is high due to the surrounding ocean.
Keep the humidity levels for rhino iguanas at 60-70%. This is the same level required by its relative, the green iguana.
Humidity and quantity are the two most important things to consider when selecting substrate.
The substrate that you use needs to hold humidity. Also, rhino iguanas are diggers, so you’ll need a deep layer of substrate.
Eco Earth and coconut fiber are good substrates. If you intend to breed rhino iguanas, sand is a good substrate.
Rhino iguanas dig holes where they lay their eggs. When females have laid their eggs, they will move mounds of earth to cover the hole.
The sand should be a minimum of 60 to 78 inches deep.
Sand is a good substrate for the enclosure whether you’re breeding rhino iguanas or not.
Sand absorbs moisture and is what rhino iguanas experience in their natural habitat. It’s also easy to clean and replace.
We recommend mixing pebble or rock substrate with the sand. Doing so will more closely replicate the natural habitat of the iguana.
It will provide a variety of terrains, which helps in enrichment, and make it easier for your iguana to burrow and construct nests.
Also known as “hides,” nest boxes provide your rhino iguana with a place for privacy, for escaping unfavorable weather, and even egg-laying.
Timber boxes make great nest boxes. Here’s how to use one:
- Cut out a hole on the side of the timber box that’s large enough for your rhino iguana to enter.
- Use sandpaper to ensure the hole has no sharp edges.
- Partially bury the timber box, so it’s below ground level.
- Line the nest box with hay or other bedding material (don’t use sawdust as it can irritate your rhino iguana).
You can also equip the nest box with a heat bulb or a heating pad.
If you use a heat bulb, cover it with wire mesh to prevent your rhino iguana from coming in contact with it.
There are simple ways to add enrichment for your rhino iguana. These include:
- Water dishes: Your rhino iguana will love soaking in a large water dish. Get a water dish large enough to soak its entire body.
- Rocks and Branches: Provide large rocks in the enclosure; your rhino iguana will enjoy using them to climb on or for basking.
You can provide branches for young rhino iguanas to climb on.
- Plants: Live plants in the enclosure can serve as a snack for your rhino iguana. Plants will also help with the humidity level.
Adding plants to the enclosure is a good way to help maintain humidity and provide your iguana with snacks throughout the day.
Pro Tip: When using plants, make sure that they aren’t poisonous to reptiles or haven’t been sprayed with parasites.
The rhinoceros iguana is mostly herbivorous; however, you must select their diet carefully.
Vegetables should form the bulk of the diet for your rhino iguana.
Because of their high sugar content, you should only offer fruits in small amounts. Fruits should make up no more than 10% of your pet’s diet.
In the wild, baby and juvenile rhino iguanas are more likely to eat insects. As they grow older, they eat increasingly less insect-matter.
Though rhino iguanas may eat insects in the wild, it’s best not to feed them to captive lizards.
Don’t offer insects as they may carry parasites. Also, the digestive system of the rhino iguana is meant to handle a plant-based diet.
Some owners make the mistake of trying to bulk up their iguana’s diet by adding insects. This has resulted in situations where the iguana experienced health issues.
Healthy foods for your rhino iguana include:
- Bell peppers
- Green beans
- Turnip greens
- Collard greens
- Sweet potatoes
- Mustard greens
- Hibiscus flowers
- Dandelion greens
- Dandelion flowers
- De-thorned cactus pads
Don’t feed your rhino iguana the following items:
- Pinky mice
- Brussel sprouts
Don’t offer these foods because they’ll disrupt the calcium to phosphorus ratio of your rhino iguana. In the wild, 95 % of a rhino iguana’s diet consists of plant matter.
We strongly recommend feeding captive rhino iguanas a diet that resembles their wild diet as closely as possible.
The bulk of the diet for the rhino iguana should be leafy greens. A smaller portion can include other vegetables, fruit, and dog kibble.
The following is a captive diet that the Taronga Conservation Society uses:
- Pears – 400 g
- Apples – 200 g
- Carrots – 200 g
- Kale – 1 bunch
- Squash – 400 g
- Pumpkin – 400 g
- Endive – 1 bunch
- Paw Paw – 400 g
- Tomatoes – 200 g
- Parsley – 1 Punnet
- Escarole – 1 bunch
- Rockmelon – 400 g
- Sweet potato – 200 g
- Alfalfa sprouts – 1 Punnet
- Mung bean sprouts – 1 Punnet
- Peas-200 g
- Beans-200 g
- Corn kernels-200 g
- Dog Kibble (low fat and soaked in water) – 150 g
To prepare the diet:
- Cut the paw paw, tomatoes, pears, apples, and rockmelon into bite-sized bits. Remove the seeds but leave the skin.
- Dice the greens into pieces small enough to swallow.
- For the pumpkin, carrots, and sweet potatoes (hard vegetables), grate them so your lizard can easily swallow them.
- Add the frozen vegetables.
- Add the mung bean and alfalfa sprouts
- Add the dog food.
This recipe is for a large collection, so it’s made in bulk and frozen. You can adjust the portion size to meet your needs.
The value of this recipe is that it shows the diversity of the diet and the ratio of the ingredients.
You should feed newly hatched and juvenile rhino iguanas daily, and adult rhino iguanas two to three times a week.
You can feed adult rhino iguanas more often in the summer.
Rhino iguanas may stop eating during the winter. This behavior is normal and is known as brumation.
Pro Tip: If you catch your rhino iguana appearing to sneeze, don’t worry. It’s a natural behavior.
Vegetables have a high level of potassium. This behavior of your rhino iguana is its way to eliminate excess salts.
It’s important to provide your rhinoceros iguana with dietary supplements. The supplements needed are calcium powder and multivitamins.
In addition to the proper foods, rhino iguanas also need a calcium powder supplement to prevent metabolic bone disease.
Provide hatchling and juveniles with calcium powder daily for their first year. Add two to three pinches of calcium powder to their regular diet.
You should mix the calcium powder with their food thoroughly so you can no longer see it.
You should also add a powdered multivitamin to your iguana’s diet.
Offer multivitamins two to three times a week for hatchlings and juveniles and once a week for adult rhino iguanas.
Pro Tip: Calcium powder and multivitamins aren’t a substitute for UVB light and a diverse diet.
The rhino iguana has a good temperament and rarely bites.
However, if it does, its bite can be severe. The jaws of the rhino iguana are very powerful, and their teeth are sharp. The rhino iguana needs powerful jaws to feed on plants like cacti.
The rhino iguana can also use its thick and muscular tail like a whip.
Being whipped by a large rhino iguana can leave bruises or welts. Also, the claws of a medium-sized or large rhino iguana can tear up your hands and arms.
Aggression isn’t a problem if you get a socialized rhino iguana.
Purchasing a baby rhino iguana from a reputable breeder is the best way to get a handleable pet.
When you first get your rhino iguana, don’t handle it for a week. This will give your rhino iguana time to get to know its new home and you.
When you start handling your rhino iguana, start with short sessions several times a day.
Doing this will give your rhino iguana a chance to get used to being handled without it getting stressed out.
To safely hold a medium or large rhino iguana, it’s best to use one hand to hold it against your body while supporting its chest firmly.
Use the other hand supports its tail and hind legs. Handling it this way will help reduce the risk of getting scratched.
When handling your rhino iguana, NEVER grab them by the tail as they may drop it.
The following are the most common health issues in captive rhino iguanas:
Respiratory infections are often caused by inadequate husbandry care, like improper humidity levels.
Respiratory infection symptoms include:
- Open-mouth breathing
- Discharge from the mouth, nose, eyes, or mouth
If you suspect that your rhino iguana has a respiratory infection, take it to a vet as soon as possible.
When the humidity level isn’t adequate, your rhino iguana can have difficulty shedding.
Sometimes known as “stuck shed,” this condition can result in serious health issues for your rhino iguana.
The old skin can remain attached to the nostrils, eyes, tail tip, or toes, possibly leading to a loss of circulation in those areas.
Young rhino iguanas, in particular, can lose body parts as a result of this.
The best way to prevent shedding problems is to monitor humidity every day, and offer a humid hide.
Metabolic Bone Disease
Metabolic bone disease is one of the most common health threats to rhinoceros iguanas.
Metabolic bone disease is caused by insufficient calcium levels and often results from inadequate UVB lighting.
UVB lighting is vital to a rhino iguana, as it allows the lizard to metabolize calcium.
If the rhino iguana’s body lacks calcium, it draws calcium from the bones to compensate for the low levels. As the bones lose calcium, they become weak.
If this condition is allowed to continue, it can lead to:
- Fractured bones
- Skeletal deformities
- Loss of muscle tone
If left untreated, metabolic bone disease is fatal.
You can easily prevent metabolic bone disease by providing calcium supplements and using UVB bulbs in the enclosure.
The following are signs that your rhino iguana is healthy:
- It eats well.
- It sheds regularly.
- It has normal bowel movements.
- It’s alert and active in its enclosure.
- Its eyes and nostrils are clear and dry.
The following are signs that your rhino iguana is unhealthy:
- It’s wheezing.
- It’s sluggish.
- It doesn’t eat well or refuses food.
- It has discharge coming from its nostrils or eyes.
- Its body lacks muscle tone, and its limbs are flaccid.
We mentioned earlier that keeping rhinoceros iguanas is expensive. The following is a general breakdown of the approximate costs:
The cost of the enclosure will depend on whether it’s custom-built or if you make it yourself. Due to the size of the enclosure needed, you can expect it to be costly.
If you have the enclosure custom-built, you can expect to pay between $2,000 and $3,000.
The price of building the enclosure yourself will depend on the materials used. If you use affordable materials, it can be considerably cheaper than buying a custom-built enclosure.
The rhinoceros iguana enclosure will require three to four heat bulbs and an equal number of lamps to house the bulbs.
The heat bulbs cost around $50-$60 dollars, while the lamps cost $60-$75 dollars.
You’ll need three to four UVB bulbs and an equal number of UVB lamps. The price of the UVB bulbs is around $50-$60, while the UVB lamps cost $60-$75.
As the UVB output of the UVB bulbs diminishes with time, you’ll have to replace them regularly (every four to six months).
You’ll need a large amount of substrate, and the price will vary depending on the substrate you use. To avoid bacteria growth, you’ll need to change the substrate monthly.
You can easily pay $100-$200 a month for substrate.
Fresh produce is another cost that will vary.
You may be able to save money by checking with your grocer to see if they would be willing to give you unsold fruits and vegetables, or sell them to you for cheaper.
Other lesser expenses include:
- Water dishes
Last but not least is the rhino iguana itself. A young captive-bred rhinoceros iguana can cost between $300-$600.
The upfront costs for keeping a rhinoceros iguana can run into thousands of dollars. The monthly maintenance will be around $300.
Yes, rhino iguanas are endangered.
The International Union for the Conservation of Nature (IUCN) has placed the rhinoceros iguana on the red list, meaning that it’s at risk of becoming extinct.
They estimate that the wild population numbers between 10,000 and 17,000.
Because of this, it’s only legal to own and sell captive-bred rhinoceros iguanas.
The risk to the wild population is largely due to the destruction of habitat and the introduction of invasive predators.
The Convention of International Trade of Endangered Species (CITES) lists the rhinoceros iguana as an Appendix I species.
Appendix I prohibits the trade of listed species without permits from both the exporting and importing country.
Before purchasing a rhinoceros iguana, ensure that the dealer has documentation to demonstrate that it was captive-bred.
Grupo Jaragua is a private organization that’s working to conserve the rhinoceros iguana in the Dominican Republic.
The company’s conservation efforts include outreach and education, habitat monitoring, habitat restoration, and land acquisition.
Grupo Jaragua is calling for improved law enforcement and the development of an island-wide conservation management plan.
Yes, rhinoceros iguanas breed readily when properly cared for.
The mating season is in late May, and females lay eggs 40 days after mating.
The female lays between five and 20 eggs, which hatch after 80-100 days.
Hatchlings start eating seven to ten days after hatching.
Young rhino iguanas eat a large amount of insects. In captivity, babies eat mealworms, crickets, and cockroaches.
Feeding baby rhinoceros iguanas insects increases their growth rate. However, keepers have successfully raised hatchlings without giving them any insects.
Male rhino iguanas are larger than females. They also have horns, parietal bulges (fatty pads located on the sides and top of the head), and larger jowls than females.
You can sex baby rhinoceros iguanas by having them probed or having a veterinarian take an x-ray.
Rhino iguanas can be good pets.
However, as with any pet reptile, there are pros and cons in keeping them as pets:
- They’re personable, intelligent, and have a good temperament.
- They’re a unique reptile as they’re uncommon in the pet trade.
- Rhino iguanas have a long lifespan. Some have been known to live for 20 years.
- They’re good-sized lizards, but they’re smaller than other big lizard species, such as green iguanas.
- Rhino iguanas are expensive to buy, and they’re expensive to keep.
- Though rhinoceros iguanas have a good disposition, they can inflict severe injuries if they do bite.
Where Can I Get a Rhino Iguana?
As you can only buy captive-bred rhinoceros iguanas, it’s best to get them from a reputable breeder.
To find a reputable breeder, we recommend screening them by asking them the following questions:
- Who do you sell to?
- What species have you bred and sold?
- As a breeder, what do you specialize in?
- Do you provide a guarantee or warranty?
- How long have you been breeding rhino iguanas?
- What kind of experience do you have as a rhino iguana breeder?
- Can you provide the names and numbers of three of your past customers? I would like to contact them to get their buying experience.
When talking to past customers, ask them:
- Were the reptiles properly packaged?
- Would you buy from this breeder again?
- Were the lizards too warm or too cold when you received them?
- How did the reptiles that you bought arrive? Were they healthy?
- Did your animal have any physical issues or external parasites?
- After receiving your animal, was the breeder responsive to your follow-up questions?
Most reputable breeders will offer you a 30-day warranty. Should the animal become sick or die, the breeder agrees to replace it with a new animal or refund your money.
We hope that this article helped determine if the rhinoceros iguana is the right pet for you.
If you don’t feel this species is the right pet for you, you may consider other lizard species like the rock iguana, black and white tegu, or the green iguana.
What do you like most about the rhino iguana? Let us know in the comments.